1) Field of the Invention
This invention relates to the camping area and, in particular, to folding trailers with an extendable room.
2) Description of the Prior Art
The use of camping trailers and recreational vehicles is well known and continues in its popularity today. Recreational vehicles are driven down the road in a self-contained unit and camping trailers are towed behind a car or other towing vehicle. Due to road limitations and the like, the width of recreational vehicles and camping trailers is restricted to certain maximums when the unit is traveling down the road. One solution for adding width to a recreational vehicle or camping trailer when set up at a campsite is to provide one or more slide-outs or movable rooms which can be extended laterally outwardly from the unit and then moved back into one or both sides thereof. Examples of prior art units including a slide-out or movable room are shown in U.S. Pat. Nos. 3,941,414; 4,049,310; 4,480,866; 4,500,132; 4,930,837; 5,154,469; 5,237,782; and 5,280,687.
The use of a laterally movable slide-out room is also known in connection with a tent camper or folding trailer as shown in U.S. Pat. No. 5,567,003 to Gill. However, the particular slide-out structure shown in the Gill patent has a number of deficiencies which make it not suited for the environments in which tent campers are typically used. The arrangement shown in the Gill patent utilizes a pair of guide tubes that are attached under the chassis or framework of the trailer. Each tube carries a horizontally disposed support shaft that is attached at one end to the slide-out and which provides straight line guidance for lateral motion of the slide-out and provides support until the slide-out can be stabilized in its final position. A problem with this arrangement is that the tubes and support shafts are totally exposed and are vulnerable to damage from rocks and other road hazards which would render the slide-out difficult or impossible to operate. The support shafts must also be heavily lubricated and will likely need constant attention to maintain adequate lubricity. In addition, when the slide-out is in the extended position, the greased areas on the support shafts are exposed to damage and dirt. In fact, the axle grease on the support shafts acts like a magnet, attracting dirt and road grime that will eventually cause binding and difficulty in operation. With the arrangement in the Gill patent, there is a serious risk that the slide-out mechanism (tubes and support shafts) would be bent or otherwise damaged either when the trailer is in the folded position, and then the slide-out could not be extended, or when the trailer is in the extended position, and then the slide-out could not be retracted back into the trailer and the trailer could not be further moved. In addition, separate stabilizer bars are needed at the outer edges of the slide-out to provide adequate support. If the slide-out is not equally stabilized in the extended position, the slide-out mechanism could bind in the extended position. Moreover, in the arrangement shown in the Gill patent, roller wheels are provided on the bottom of the slide-out and directly engage the floor of the trailer. These roller wheels tend to leave impressions on the trailer floor and scratch, crease or crack the floor when the slide-out is moved into and out of the trailer. Furthermore, the design of the Gill patent requires a large pulling force to extend the slide-out from the trailer and a large pushing force to retract the slide-out back into the trailer.